LexA-like (IPR039418)

Short name: LexA-like

Overlapping homologous superfamilies

Domain relationships


Peptidase S24 LexA-like proteins are involved in the SOS response leading to the repair of single-stranded DNA within the bacterial cell [PMID: 17883408]. Proteins containing this domain includes LexA, MucA and UmuD. LexA (EC: is the repressor of genes in the cellular SOS response to DNA damage [PMID: 8798618].

The LexA-like proteins contain two-domains: an N-terminal DNA binding domain and a C-terminal domain (CTD) that provides LexA dimerization as well as cleavage activity [PMID: 11551506]. They undergo autolysis, cleaving at an Ala-Gly or a Cys-Gly bond, separating the DNA-binding domain from the rest of the protein [PMID: 7845214].

The LexA, UmuD and MucD proteins interact with RecA, which activates self cleavage either derepressing transcription in the case of LexA [PMID: 10692372] or activating the lesion-bypass polymerase in the case of UmuD and MucA. UmuD'2, is the homodimeric component of DNA pol V, which is produced from UmuD by RecA-facilitated self-cleavage. The first 24 N-terminal residues of UmuD are removed; UmuD'2 is a DNA lesion bypass polymerase [PMID: 10692372, PMID: 11483531]. MucA [PMID: 9925794, PMID: 11016960], like UmuD, is a plasmid encoded a DNA polymerase (pol RI) which is converted into the active lesion-bypass polymerase by a self-cleavage reaction involving RecA [PMID: 11114935].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.